The present invention disclosed herein relates to an amplifier circuit, and more particularly, to a current-voltage conversion amplifier circuit.
An amplifier circuit means an electronic circuit amplifying the voltage, current, and power of an input signal to generate an output signal. The amplifier circuit includes a voltage amplifier circuit, a current amplifier circuit, a power amplifier circuit, and a current-voltage amplifier circuit converting current signal into voltage signal and amplifying it.
A high-impedance preamplifier and a transimpedance amplifier are mainly used as the current-voltage conversion amplifier circuit. The high-impedance preamplifier improves the reception sensitivity by increasing a load resistance to increase an input voltage. The transimpedance amplifier uses a resistance in a feedback loop. The thermal noise of the transimpedance amplifier is reduced by the resistance. Additionally, the transimpedance amplifier has a more improved dynamic range compared to the high-impedance preamplifier.
However, the transimpedance amplifier requires a resistance of hundreds of ohms to process a small current signal. Therefore, when the transimpedance amplifier is used in the current-voltage conversion amplifier circuit, its power consumption is high and its circuit area is increased.